When an integrated circuit is marketed, a data sheet for the integrated circuit is usually produced for distribution to electrical engineers that may incorporate the integrated circuit into products that they are designing. Several data sheets are gathered together to form a data book that is published by the integrated circuit company. These data books describe the integrated circuits produced by the integrated circuit producer.
The data sheet about the integrated circuit contains a large number of specifications that define the exact behavior of the integrated circuit. For example, operating temperature, operating voltages, and several timing specifications are provided on the data sheet. Two of the timing specifications that are often provided the minimum valid time for an output signal and the maximum valid time for an output signal. A minimum valid time defines the minimum amount of time that the output signal must be available on the output line after a clock cycle has started. The output signal must not change before this minimum valid time has expired. The maximum valid time defines a maximum amount of time that may pass after a clock cycle has started before which the output data signal must be stable. Thus, the output signal must be stable before the maximum valid time ends.
During the market lifetime for an integrated circuit, the process technology used to build the integrated circuit may change several times. Furthermore, the integrated circuit may be redesigned in the inside to make it more efficient, adapt to new process technologies, and to use less power. These design changes may change the speed at which the integrated circuit operates. However, unless the integrated circuit device is introduced as a new modified integrated circuit, the integrated circuit must still fulfill the timing requirements of the original integrated circuit as published in the data page in a data book. Therefore, it would be desirable to have a method and apparatus for adjusting the output signals of a modified integrated circuit such that it fulfills the timing requirements of the original integrated circuit that are published in the data book.